In operations such as esophagus reconstruction after esophagus extraction, gastrectomy, small-intestine and large-intestine resections, etc., there have been steadily studied operating methods and instruments for more completely suturing both resected portions.
Specifically, among operations on the inside of a human body, for example, an operation of connecting an end of the esophagus, which is located at a position where it is difficult to perform a specific operation, to the small intestine at the inside of a diaphragm after a total gastrectomy, an operation of connecting the remaining portion of a rectum to a large intestine after resecting the rectum up to a portion close to an anus, etc. have many difficulties. That is, in order to anastomose the esophagus to the small intestine after performing the total gastrectomy, a major operation of cutting ribs and the diaphragm to enter a chest should have been performed. In a case of operation on the rectum, the anus should be removed and the large intestine should be exposed to the abdomen, so that a disorder of drawing out excrements should be left.
An intraluminal stapler was developed to overcome the difficulties of operation, which is used for anastomosing an esophagus to a small intestine or anastomosing intestines to each other, cutting off a specific portion, and anastomosing blood vessels to each other. Details of such an intraluminal stapler are disclosed in U.S. Pat. No. 5,104,025.
After cutting off an intestine, the cut-off ends of the intestine are sutured with the intraluminal stapler so as to keep the connection between the intestines. This process requires most time and labor in operations and also requires a constant result. The intraluminal stapler for simply and securely performing the process is classified into a circular stapler (EEA) and a linear stapler. The linear stapler is further classified into a stapler (GIA) cutting and suturing a tissue and a stapler (TA) only suturing a tissue.
In such intraluminal staplers, staples are pressed by a push member, penetrate an operating portion, and then are pressed by a support member having grooves, so that the staples are bent in an arc shape. The staples used in an operation on a human body have the same appearance as general stationery staples, but have a size and a material different from the stationery staples. Therefore, such a type has a bad influence on the sutured operating portions. Now, problems related to this shape will be described in more detail with reference to FIG. 7.
FIG. 7 is a schematic diagram illustrating working steps of the conventional staple, where the process of suturing a tissue using the staple is illustrated step by step. The state of suturing a tissue using the staple will be described as follows.
First, as shown in (A) of FIG. 7, at the upside, a staple 70 is pressed by a push member 73 and at the downside, a support member 75 having grooves 751 for bending the staple 70 is provided. The staple 70 penetrates suturing tissues 7000 and 7100 by pressing the staple 70 with the push member 73 in the upper arrow direction, and the support member 75 gets close to the lower portion of the suturing tissues 7000 and 7100 in the lower arrow direction.
Since the push member 73 and the support member 75 work simultaneously in this way, as shown in (A) of FIG. 7, leg portions 70a of the staple 70 extending downwardly come in contact with the grooves 751 of the support member 75 and the leg portions 70a are bent in a rounded shape while the staple 70 penetrates the suturing tissues 7000 and 7100.
As the push member 73 and the support member 75 are continuously moved in the arrow directions, as shown in (C) of FIG. 7, the leg portions 70a of the staple 70 are completely bent, come in contact with the lower portion of the suturing tissue 7100, and then closely suture the suturing tissues 7000 and 7100. However, since the leg portions 70a of the staple 70 are opposed to each other and bent in a rounded shape, as indicated by the central arrow, a repulsive force is applied to respective ends of the leg portions 70a. On the contrary, as indicated by both side arrows, an attractive force due to the bending is applied to the leg portions 70a close to the penetrated portions.
Accordingly, since tensions having different directions are applied to the same leg portions 70a, the tensions have an influence on the suturing tissues 7000 and 7100, so that the tensions are made uneven. Since the tensions are uneven, the suturing tissues positioned at the ends of the leg portions 70a may be bitten and torn, and the suturing tissues positioned at the leg portions 70a close to the penetrated portions may be lack of tension, thereby causing bleeding or leakage.
Specifically, when an excessive force is applied at the time of suturing the operating portion using the intraluminal stapler as shown in (D) of FIG. 7, the ends of leg portions 70a of the staple 70 may re-penetrate the suturing tissues 7000 and 7100 toward the upper portion of the suturing tissues 7000 and 7100. Therefore, total four holes are formed in the suturing tissues 7000 and 7100, thereby causing the bleeding from the suturing tissues 7000 and 7100. In addition, the sutured portion may be opened even after the operation, thereby requiring a re-operation.